Thanks guys!
I'm a tad dense so forgive me for asking so many questions! I'll look for another casting number.. the one that I have is from the pass side (3769716) but I'll look on Tuesday when I'm at the garage and see if there's another one.
Meanwhile, the info I got from American Classic about the STAMPED ID is from:
http://www.americanclassic.com/paint.htm?p1=engines and that shows a "BE" as 1960... but maybe I'm interpreting it wrong.